1. Field of The Prior Art
This invention relates to a mechanical code lock, and particularly to a mechanical code lock having tumbler beads which can be changed to different combinations by selectively transferring some beads from one group to another group of tumbler holes by means of a code key.
2. Brief Description of Related Prior Art
Mechanical code locks whose combinations can be changed by using a code card are known in the art. For example, U.S. Pat. No. 4,149,394 discloses a mechanical lock having tumbler pins and tumbler balls which can be changed into various combinations by using different code cards. The lock is unlocked by using a key card which is operative only when the code card is present in the lock.